1. Field of the Invention
The invention relates to systems and method of execution of treatments and data accumulation (including imaging data) of those treatments to provide ablation of tissue in a medical procedure. A system and method provides highly effective levels of ablation, especially in malignant tissue target areas so that greater assurance in removal of malignant tissue is afforded during a first procedure. By using imaging techniques and data to differentiate between malignant and non-malignant prostate tissue, tissue removal such as by means of ablation is directed to the malignant tissue, for preservation of the non-malignant tissue in the prostate and surrounding region, thereby minimizing the destructive effects of tissue removal.
2. Background of the Art
Prostate cancer is widely believed to be the most common cancer in men and the second most common cause of death due to cancer. There were approximately 230,000 reported cases of prostate cancer diagnosed in North America in 2005 and over 30,000 deaths. Furthermore, the true prevalence of the disease has been calculated at more than 25% of men over 55. The standard treatments for localized prostate cancer are radical surgery or radiotherapy. These entail ablation of the entire prostate with some degree of unintended collateral damage to surrounding organs. The standard belief is that prostate cancer is a multifocal disease so that treatments are required that target the entire prostate gland. These treatments are neither completely curative nor devoid of side effects. Recent data suggest that this may not be correct in all cases. For the majority of patients low grade and low volume prostate cancer is the prevalent pathological finding and offers minimal risk of morbidity or mortality. Indeed, many believe that radical intervention using standard treatments might offer more harm than good and a strategy of deferred treatment is now being adopted. However, even in this favorable group approximately 20% of men can be expected to die from their disease if followed for long enough.
A new paradigm of therapy is to target selective therapeutic destruction of only the region of malignant (tumor) tissue within the prostate. A histological analysis of over 900 prostatectomy specimens removed for prostate cancer suggest that a solitary dominant lesion is the source of extracapsular in over 80% of patients and thus the likely source of extraprostatic spread. Destruction of this single site is likely to significantly decrease the risk of progression and increase cancer control with minimal side effects. One significant issue in laser ablation is assuring appropriate delivery of energy into the tissue to assure that all malignant tissue within the target area of ablation is removed. Applicant has determined that variations in ablation from single treatments, multiple treatments, single laser ablation elements and even multiple ablation elements have not appropriately provided a system and method that effectively reduces the need for multiple treatments because of the inability to create a uniformly heated and confluent zone of ablation of ablation throughout the target zone, or because of tissue inhomogeneity, needle deflection occurs making accurate target acquisition impossible due to deterioration of image acquisition with each attempted needle pass, or creates too large a window of low energy deposition insufficient for tumor destruction but sufficient to damage adjacent functional tissue such that there is a need for additional treatments. The last issue would create a situation wherein upon later discovery of the insufficiency of malignant tissue removal, more extensive volumes of tissue removal (including adjacent ancillary, non-malignant tissue) to assure a final undesired result.